This invention relates to polishes. More particularly, it relates to silicone emulsion polishes and dressings which form detergent-resistant, durable protective coatings on solid surfaces.
The present invention also relates to the preparation of the emulsions and polishes of the present invention by the process of emulsion polymerization.
Silicone emulsion polishes and dressings, commonly used to improve the appearance of and to protect household products, luggage, fabrics, marine and auto vinyl, sporting goods, and the like, are favored for their glossiness and ease of application; however, they lack durability, especially after detergent washing, and must be frequently reapplied.
Amine-catalyzed resinous polysiloxane wood varnishes are disclosed in U.S. Pat. No. 3,350,349 to Hyde (incorporated herein by reference), but their application, varnish-like properties and the resultant hard, dry film make them unsuitable for many polishing needs.
Sanders, U.S. Pat. Nos. 4,246,029 and 4,247,330, discloses an aqueous emulsion containing (1) a mixture of silicone compounds consisting of (a) an aminofunctional silicone fluid and (b) a cyclic siloxane, (2) an aliphatic alcohol having from 1 to 4 carbon atoms, (3) sufficient carboxylic acid to neutralize the aminofunctional groups and (4) cationic emulsifying agents, if desired. Such aqueous emulsions are said to be storage stable and suitable for dispensing in automatic car washes to impart a detergent resistant protective coating.
Martin, U.S. Pat. No. 3,960,575, teaches that improved detergent resistant polish compositions can be prepared by adding aminofunctional silicone fluids obtained by equilibrating with cyclic siloxanes to conventional polish compositions.
While each of the foregoing discloses useful polish compositions, the emulsions are prepared by mechanical means well known to those skilled in the art and thus do not possess properties such as durability and resistance to washing to the extent which may be desired. Consequently, there has been a growing need to develop an easily applied polish, suitable for diverse polishing needs, which will exhibit improved durability, resist washings, and afford increased protection to polished surfaces.
The present applicants, in an attempt to overcome the shortcomings of the prior art, prepared emulsions by the process known as emulsion polymerization rather than by the heretofore accepted mechanical methods. Those skilled in the art recognize that emulsions prepared by emulsion polymerization are characterized by extreme stability and extremely fine particle size. Moreover, those skilled in the art appreciate that the problems associated with preparing emulsions by emulsion polymerization are substantially different from those associated with preparing emulsions by mechanical means.
Hyde et al., U.S. Pat. No. 2,891,920, were the pioneers in the field of emulsion polymerization. Hyde et al. recognized that improved emulsions could be prepared by carrying out the polymerization of low molecular weight siloxanes while the siloxanes were dispersed in an aqueous media instead of emulsifying higher molecular weight siloxanes which were dissolved in an organic solvent. In carrying out the method of Hyde et al. the siloxane is first dispersed in the water, preferably with the use of an emulsifying agent, and a suitable polymerization catalyst is thereafter added to promote polymerization to the desired degree. Polymerization is carried out below the boiling point of water, although temperatures above 100.degree. C. can be employed if the polymerization is carried out in a closed system. Hyde et al. reveal that as the polymerization proceeds the viscosity of the siloxane increases but the size of the emulsion droplets decreases and it is believed that this is what causes the extremely stable emulsions obtained by emulsion polymerization.
Oppliger, U.S. Pat. No. 3,208,911, discloses a method for treating hair to improve the appearance, manageability and softness of the hair consisting essentially of submitting the hair to the action of an ionic oil-in-water emulsion, said emulsion being composed of an organosiloxane in an amount of from 0.01 to 90 percent by weight based upon the total weight of the emulsion and an ionic emulsifying agent in an amount of from 2 to 25 percent by weight based upon the weight of the organosiloxane and an alkaline catalyst in an amount of from one alkaline molecule per 100 silicon atoms to one alkaline molecule per 50,000 silicon atoms, inclusive, and the necessary water to give the desired solids content, said alkaline catalyst being selected from the group consisting of (a) R.sub.4 NOH and (b) R.sub.4 NX admixed with Q, wherein R is alkyl, X is an acid anion, and Q is an alkaline compound selected from the group consisting of ammonia, alkali metal hydroxides, alkali metal carbonates and organic amines, said ionic oil-in-water emulsion being prepared by polymerizing the organosiloxane in an aqueous medium in the presence of said alkaline catalyst until a viscosity of 6.5 cs. to 2.5.times.10.sup.6 cs. is obtained.
Findlay et al., U.S. Pat. No. 3,294,725, discloses an emulsion polymerization process similar to that of Hyde et al., however, Findlay et al. teaches the use of a surface active sulfonc acid as a polymerization catalyst rather than a strong mineral acid or strong alkali. A nonionic or anionic emulsifying agent can be employed if so desired.
Axon, U.S. Pat. No. 3,360,491, relates to emulsion polymerization of organosiloxanes wherein the polymerization catalyst is an organic sulfate of the general formula ROSO.sub.2 OH, wherein R is a monovalent aliphatic hydrocarbon radical of at least 6 carbon atoms. As is the case in Findlay et al., a nonionic or anionic emulsifying agent can be employed if so desired.
Cekada et al., U.S. Pat. No. 3,532,729, teaches the preparation of mercaptosiloxanes by emulsion polymerization.
Sorkin, U.S. Pat. No. 3,624,017, discloses an aqueous emulsion of a copolymer of 80 to 98 mole percent dimethylpolysiloxane and 2 to 20 mole percent R SiO.sub.3/2 in which R is methyl or vinyl, said emulsion having been prepared by emulsion polymerization of a mixture of dimethylpolysiloxane and R SiX.sub.3, in which X is a hydrolyzable group producing a water soluble by-product such as halogen, ##STR1##
--ON (R.sup.1).sub.2 in which R.sup.1 is a monovalent hydrocarbon or halocarbon radical and R.sup.2 is a divalent hydrocarbon or halohydrocarbon radical. It should be noted that the nitrogen-containing radicals of Sorkin are hydrolyzable and hence will not remain bonded to the siloxane chain in an aqueous medium.
Campbell, U.S. Pat. No. 3,634,297, provides a process for binding a pigment to glass fabric which comprises (A) applying to the glass fabric an aqueous emulsion of a copolymer consisting essentially of (a) 50 to 90 mole percent of (CH.sub.3).sub.2 SiO units and (b) 10 to 50 mole percent of R SiO.sub.3/2 units, wherein R is an alkyl or alkenyl radical of 1 to 3 carbon atoms, the 3,3,3-trifluoropropyl radical, or a phenyl radical, said copolymer having been prepared by emulsion polymerization; and a water dispersible pigment; and (B) drying the glass fabric.
Ikoma, U.S. Pat. No. 3,697,469, describes an emulsion polymerization process involving (i) emulsifying, in water containing a salt-type anionic surface active agent, an organosiloxane of the formula ##EQU1## where R is a hydrogen atom or a monovalent hydrocarbon radical or a halogen substituted monovalent hydrocarbon radical, and a has an average value of 1 to 3, and then (ii) contacting said emulsion with an acid-type cationic exchange resin so that said surface active agent may be ion-exchange from salt type into acid type, thereby acquiring catalytic power and at the same time starting the polymerization of said organosiloxane by making said emulsion an acid medium with a pH value of less than 4.
Backderf, U.S. Pat. No. 3,706,697, relates to aqueous emulsion polymerization of acryloxyalkyl-alkoxysilane, alkyl acrylic esters, and optionally other vinyl monomers to provide copolymers curable at low temperatures. The acryloxy functional site of the silane is said unexpectedly not to hydrolyze upon polymerization and thereby serve as a crosslinking site for reaction with the alkyl acrylic ester.
Hilliard, U.S. Pat. No. 3,898,300, describes an emulsion polymerization method to produce a polymeric styrene-acrylonitrile-polyorganosiloxane composition.
Huebner et al., U.S. Pat. No. 4,288,356, discloses a method of blending an emulsion of an emulsion polymerized compolymer of an organic monomer and an organosilicon monomer and an emulsion of a polydiorganosiloxane to provide a reinforced elastomeric product.
The prior art directed to emulsions prepared by emulsion polymerization does not disclose aminofunctional emulsion polymerized polysiloxanes or the use of such polysiloxanes to provide improved polishes. Also, the prior art does not disclose the use of certain ethers as emulsifiers so as to allow utilization of higher temperatures and faster emulsion polymerization. Nor does the prior art disclose the use of cationic catalysts, especially in combinations with the aforementioned ether emulsifying agents, so that emulsion polymerized polysiloxane emulsions can be stripped of cyclic or other low molecular weight siloxanes from which they were prepared. Furthermore, prior art emulsion polymerization processes do not reveal the advantage of including a mixture of alkoxy functional silanes and aminofunctional silanes in the resulting emulsion compositions.
It has now been discovered that aminofunctional silicone polymer emulsions prepared by emulsion polymerization can be used to form easily applied polishes which adhere well to surfaces and resist removal even from many detergent washings. Used as textile finishes, the aminofunctional emulsions impart good hand qualities and water repellency to fabrics.